Effect of LiCl flux on the red ZnS : Sm phosphors fired in reductive atmosphere

ZnS:Sm phosphors with strong red emission can be prepared by solid state re action fired in a reductive atmosphere. Using LiCl as the fluxing agent fav ors the crystal growth of ZnS as well as increasing the content of the hexa gonal phase in ZnS. The higher content of the hexagonal phase and evenly-di stributed samarium compound on ZnS can induce greater light energy absorpti on and result in better photoluminescence emission intensity and color puri ty. The red emission intensity of ZnS:Sm phosphors is increased about 5 tim es with the addition of LICl flux agent compared with the addition of Sm al one without any flux agent. The optimal concentration of LiCl flux is 2.0 m ol% for ZnS with doping 0.2 mol% Sm phosphors fired in a reductive atmosphe re. (C) 2000 Elsevier Science Ltd and Techna S.r.l. All rights reserved.